package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private IUserService iUserService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        // 获取用户id
        Long userId = UserHolder.getUser().getId();
        String key = "follows:" + userId;
        // 判断关注还是取关
        if (isFollow) {
            // 关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean save = save(follow);

            if (save) {
                // 把关注的用户id 放入redis的set集合 sadd userId followerUserId；
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        } else {
            // 取关
            boolean remove = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId)
                    .eq("follow_user_id", followUserId)
            );

            if(remove){
                // 把关注的用户的id移除
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result followCommons(Long id) {
        Long userId = UserHolder.getUser().getId();


        String key1 = "follows:" + userId;
        String key2 = "follows:" + id;

        // 求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);

        if(intersect == null || intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }

        List<Long> collect = intersect.stream().map(Long::valueOf).collect(Collectors.toList());

        List<UserDTO> res = iUserService.listByIds(collect).stream().map(user -> {
            return BeanUtil.copyProperties(user, UserDTO.class);
        }).collect(Collectors.toList());

        return Result.ok(res);
    }

    /**
     * 是否关注了followUserId
     *
     * @param followUserId
     * @return
     */
    @Override
    public Result isFollow(Long followUserId) {
        // 获取用户id
        Long userId = UserHolder.getUser().getId();

        // 查询 是否关注
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count > 0);
    }

}
